1. Field of the Invention
This invention relates to a robot for driving a vehicle such as an automobile, in particular for the case where the performance of the vehicle is to be tested using a chassis dynamometer.
2. Description of Related Art
In conventional vehicle tests such as automobile emissions tests and fuel-cost tests, the automobile is mounted on a chassis dynamometer and is then operated according to a predetermined driving profile. In order to reduce labor costs and improve test repeatability, robots have been used to "drive" the vehicle.
An example of a robot apparatus for driving an automobile is disclosed in the laid-open Japanese Utility Model Application No. Sho 63-190,944 has been known as said robot for driving an automobile. This apparatus for driving an automobile is provided with an actuator that comprises an arm, which operates the accelerator pedal, and a driving device, which reciprocates the arm. The degree to which the accelerator is applied is regulated by reciprocating the arm to operate the accelerator pedal so that the test automobile is "driven" according to a previously defined driving or operational profile.
When a motor is driven according to an operational profile using such a conventional robot, however, when the motor pops out of gear or too great a difference arises between an intended car speed and the actual car speed, the robot disengages the accelerator actuator from the accelerator pedal, shifts the automobile's gear-shift lever to a neutral position by a shift lever-operating actuator, and the engine is shut off.
In the above-described conventional robot for driving an automobile, however, the robot does not directly turn the vehicle's ignition key, but rather it switches wiring within an engine compartment with the respective relays of a controller in order to stop the engine. In addition, in the case where the controller's power source is switched off due, for example, to an electric power failure, the accelerator actuator is disengaged from the accelerator pedal by using a mechanical member such as a spring.
Using a conventional robot for driving an automobile, therefore, when some serious problem occurs, the robot cannot shut off the vehicle's engine in a secure manner. The automobile's engine and transmission may thereby suffer severe damage; indeed, in some circumstances, the automobile itself may even jump out of the chassis dynamometer and endanger those around it.